Selector control mechanism



NOV. 7, 1933. I c p G H SELECTOR CONTROL MECHANISM Filed 001;. 2, 1930lnventog'.

Charles T. e h.

by His Attorney.

Patented Nov. 7, 1933 UNITED STATES PATENT OFFICE SELECTOR CONTROLMECHANISM Charles P. Geyh, Oaklyn, N. J., assignor to GengralkElectricCompany, a corporation of New Application October 2, 1930. Serial No.486,001

6 Claims.

electric motor and means for tor to move a control means operating themofor the apparatus,

selectively to any one of a plurality of predetermined positionscorresponding to any one of a corresponding number of preselectedconditions of operation or signal channels to which the apparatus may beresponsive. In a copending appplication of Charles R. Garrett, SerialNo. 480,464, entitled Remote control system for radio receivingapparatus and the like, a remote control system of the above characteris shown and described, and includes a selector control mechanism havinga plurality of reversing andcontrol switches arranged to be operated bya series of cams for stopping the motor and the controlled deviceexactly at any one of a corresponding number of preselected positions.

It is more particularly to system of this character that a remotecontrol the present invention relates, and has for its object to providean improved, simplified and compact selector control mechanism arrangedto combine any number of reversing switches with a control meanstherefor whereby the cams are eliminated.

The invention will better be understood from the following descriptionwhen taken in connection with the accompanying drawing and its scopewill be pointed out in the appended claims. In the drawing, Figs. 1 and2 are front and side views respectively, both partly in section, of

a selector control mechanism embodying the invention; and Fig. 3 is awiring diagram of a remote control system embodying the selector controlmechanism of Figs. 1 and 2.

Referring to Figs. 1 and 2, 5 is a control shaft for an apparatus, suchas a radio apparatus 6,

on which shaft is mounted a commutator or switching means having aninsulating body or cylindrical core 7 secured to the shaft 5, and twoelongated equal segments 8 and 9 mounted on the core and having a shortgap 10 of insulating material between two of the adjacent edges of thesegments.

The insulating material is flush with the segments and provides withthem a smooth cylinder.

In the present example, the control shaft Sis connected directly withthe apparatus 6 which it controls. This apparatus is represented as avariable tuning condenser.

For electrical remote control, the condenser 6 and the control shaft 5are driven by suitable electrical means such as a reversible electricmotor 11, and a reduction gearing including a worm 12 mounted on themotor shaft 13 and meshing with a worm gear 14 mounted on the controlshaft 5. The motor is provided with a reversing circuit including tworeversing leads 15 and 16 and a reversing circuit return lead 17,together with a pair of leads 18 through which it is energized. With thesupply leads 18 energized the motor remains at rest until either one ofthe leads 15 or 16 is closed with the return lead 17, the closure ofeither of the leads 15 or 16 with the lead 17 causing the motor tooperate in one direction or the other.

The motor is preferably of the alternating current, shifting-field typearranged with the leads 15, 16 and 1'7 connected with suitable shadingpoles for effecting the reversing and stopping operation of the motor asabove described. However, any suitable reversible, electric motor may beemployed, which is provided with a suitable reversing circuit having tworeversing leads and a return lead therefor as above described. Theoperation of the motor and its connection in circuit with the apparatuswill be described hereinafter. in connection with Fig. 3.

Concentric with and carried by the commutator .cylinder are a pluralityof annular rings 19 of insulating material. The rings are freelyrotatable upon the commutator cylinder and are in number equal to thenumber of preselected positions to which it is desired to moveautomatically the controlled device 6. In the present example sevenrings are provided. Each of the rings is provided with an inner recess20 in which is mounted a flexible spring contact member or brush. 21secured in the recess and to the. ring, by suitable means such as a pin22. The contact member is provided with a thin contact end 23 which issprung into engagement with the commutator cylinder and is of suchthickness that it may rest upon the insulating material of the gap 10without making contact with either of the commutator segments,substantially as indicated carries a contact 21 as above described, butonly one appears in the drawing for the purpose of simplifying thelatter.

The contact or brush carrying rings 19 may be rotated to provide anadjustment of each contact 21 and may be held in an adjusted position byany suitable means. As a preferred means and as shown in the presentexample, a worm 24 is provided in connection with each adjusting ring 19and is arranged to engage teeth 25, moulded or cut in the periphery ofthe ring. These teeth are preferably straight but may be concaved ifdesired. Each worm 24 is mounted upon a suitable shaft 26 carried in abracket 27 secured to a suitable support such as a panel 28. Each of therings is locked against rotational movement by the worm which engages itand may be moved to adjust the positions of the contact 21 carried byit, by rotation of the shaft 26 through the medium of control knob 29provided on the end of the shaft of the panel front.

With the above described arrangement the commutator cylinder is arrangedto rotate with the control shaft 5 while the contact carrying or contactadjusting rings are held'in fixed positions of adjustment. With theusual tuning device of a radio receiver for example, havingsubstantially 180 degrees of rotation, the length of the commutatorsegment in a two-segment device is such that the contact 21 of any ring,such as that shown in Fig. 2, may remain in contact with either segmentthroughout the rotational range of the tuning device.

The peripheral length of the helical teeth in each ring is such that thering may be moved through substantially the same range of movement asthe control or tuning device 6, that is, in the present examplesubstantially 180 so that the contact carried by the ring may be movedto any desired point of adjustment corresponding to any desired positionin the range of movement of the controlled device.

Since the range of movement of the commutator and of the contactadjusting ring is less than a full revolution, electrical connectionsmay be made with said contacts 21 and with the commutator segments 8 and9 through the medium of flexible leads thereby eliminating slidingcontacts which introduce contact resistance and are often a source offaulty operation. In Figs. 1 and 2 the flexible lead connections for thecommutator segments 8 and 9 are indicated at 30 and 31 respectively,while the flexible lead connections for the various contacts 21 carriedby the rotata ble rings 19 are indicated at 32.

It will be noted that the adjusting rings for the contacts or brushes 21are relatively thin and are placed closely, adjacent to each other. Thisarrangement serves to reduce the length of the selector controlmechanism and to render the mechanism compact. .The length of thecommutator cylinder is then only such as to carry the number of ringsrequired for the particular apparatus with which the mechanism is usedand to provide a slight additional length at each end of the commutatorcylinder for the purpose of making electrical connections thereto. Whilethe rings do not tend ordinarily to move longitudinally of the'commutator cylinder, it is obvious that they may be secured againstlongitudinal movement by'similar rings at each end of the series ofadjustable rings, secured to the commutator cylinder. In order tosimplify the drawing such confining rings are not shown. It will benoted. however, that space for such rings is provided on each end of thecommutator cylinder.

It will further be noted that because of the compactness of the selectorcontrol mechanism afforded by the thin contact adjusting rings, theworms provided for adjusting each ring are staggered alternately aboveand below on opposite sides of the selective control mechanism orcommutator. This arrangement provides two rows of adjusting knobs 29 onthe panel and prevents the adjusting worm for each contact adjustingring from interfering with others on either side thereof. From thedrawing it will be seen that the selector control mechanism of thepresent invention is of relatively small size while providing aplurality of positions of adjustment.

Referring now to Fig. 3 along with Figs. 1 and 2, the selector controlmechanism of the present example is shown in connection with a remotecontrol, preselected-channel tuning system. The reversing leads 15 and16 of the motor 11 are each connected with one of the commutatorsegments 8 and 9. The adjustable contacts or brushes 21 are connectedthrough suitable selector leads 33 each to one contact of a series ofselector switches 34 located in a remote selector unit 35. A secondcontact 36 for each of said switches is connected through a lead 37,with the reversing circuit return lead 1'7. The various circuit leadsindicated at 38 between the selector control mechanism and the remotecontrol unit 35 are pref erably carried in a cable. The motor isenergized from alternating current supply leads indicated at 39 whichare connected with the motor supply leads 18 through a control switch40.

The above described circuit arrangement is such that the reversingcircuit is completed through the selector control mechanism from eitherone of the leads 15 and 16, through the reversing circuit return lead17, to operate the motor in one direction or the other. As will be seenfrom the drawing the reversing circuit is completed through one of thecommutator segments, one of the contacts 21, one of the selector leads33 and one of the selector switches 34, the contact and leads beingdetermined by the closure of one of the control switches 34.

With the motor energized from mains 39 by closing switch 40, the motorwill operate in the directions indicated in Fig. 3 by the arrows placedupon the commutator, when the reversing circuit is completed through thesegment adjacent each arrow and will stop when the reversing circuit isopened by one of the contacts 21 reaching the gap in the commutator. Theselected one of the contacts to effect the operation of the motor isdetermined by closure of a selected one of the switches 34.

It will thus be seen that the controlled device may be moved to a seriesof preselected positions corresponding to preselected conditions ofoperation, or preselected signal channels in the case of a radioapparatus, by adjusting a contact carrying or adjusting ring to suchposition such that its contact 21 will lie in the gap between thecommutator segment when the motor has driven the controlleddevice to thedesired position. Such positions of adjustment are obtained in each caseby adjusting the ring carrying the contact selected for that position bymeans of one of the control knobs 29 until the contact 21 is moved to aposition wherein its contact end 23 lies on the gap 10 in the commutatorsegment while the controlled device, such as the condenser 6 in thepresent example, is in a desired position of adjustment.-

It will be appreciated that the difference in dimension between the gap10 in the commutator and the thickness of the metal of the contact end23 at the radius of contact determines the angular displacement or errorin adjustment which is permitted for the controlled device withoutcausing a corrective movement of the motor. Stated in another way, theaccuracy of the remote control depends for the width of the gap 10 inthe commutator with respect to the thickness of the contact end 23 ofeach contact 21. This width should for this reason be greater only by anamount sufficient to fully open the reversing circuit without permittingfurther movement of the commutator and controlled device in eitherdirection without closing the reversing circuit in one direction or theother. It will thus be seen that this arrangement provides for accurateadjustment of the tuning control device 6 to a desired position underautomatic or remote control after the initial adjustment is made.

While seven adjusting rings and contacts are shown in the presentexample, it will be appreciated that a greater or lesser number may beprovided.

The above described switch arrangement has the further advantage thatwhen applied directly to a movable controlled device, as is preferable,it provides in connection therewith a constant mechanical resistanceload since the contact is made electrically and not mechanically, thatis, the brushes move in contact with a smooth cylinder. It also has theadvantage that in production a single commutator cylinder is requiredhaving two simple contact segments and the contact or brush carryingmechanism involves duplicate units, each unit being a simple ring and acontact carried by the ring. The teeth on each ring are straight teethand are not concaved, thereby making for simplicity of construction inmanufacture.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. A remote control system for radio receiving apparatus and the like,including a control shaft, a selector control mechanism connected withsaid shaft, said mechanism including a rotatable cylindrical commutatordevice having two segments and having insulating gaps between saidsegments, a plurality of brushes for the commutator, said brushes beingadjustable circumferentially of the commutator and being adapted to liein said insulating gaps and out of'contact with said segments when movedto an adjusted position and means arranged in a common plane forindividually adjusting said brushes and holding the same in positions ofadjustment.

2. A remote control system for radio receiving apparatus and the like,including a control shaft,

a rotatable commutator device connected with said shaft and having twoconducting segments, said segments having adjacent edges and insulatinggaps between said edges, control circuit leads directly connected eachwith one of said segments,

a plurality of brushes for the commutator, said brushes being adjustablecircumferentially of the commutator and being adapted to lie in saidinsulating gap and out of contact with said segments when moved to anadjusted position, means arranged in a common plane for individuallyadjusting said brushes and holding the same in positions of adjustment,and flexible leads directly connected to each one of said brushes forconnection to a selective control circuit.

3. A multiple-circuit reversing switch including in combination, acommutator cylinder having two contact segments and an insulating gapbetween said segments, a plurality of annular rings rotatably mountedupon said commutator cylinder, a brush carried by each of said rings andarranged to contact with said commutator cylinder, each of said brusheshaving a contact end adapted to lie in the gap in said commutatorcylinder and out of contact with both of said segments when moved to anadjusted position, and means for adjusting each of said rings to adjustthe positions of said brushes.

4. A multiple-circuit reversing switch including in combination, acommutator cylinder having two contact segments and an insulating gapbetween said segments, a plurality of annular rings rotatably mountedupon said commutator cylinder, a brush carried by each of said rings andarranged to contact with said commutator cylinder, each of said brusheshaving a contact end adapted to lie in the gap in said commutatorcylinder and out of contact with both of said segments when moved to anadjusted position, and means for adjusting each of said rings to adjustthe positions of said brushes, said means including a series of teethprovided on a portion 5 of the periphery of each of said rings, a wormarranged to engage each of said rings through the medium of. said teeth,and means for rotating each of said worms to adjust said rings.

5. A selector control mechanism for an electrical remote control systemfor radio receiving apparatus and the like, including a control shaft, acommutator cylinder mounted on said shaft, said cylinder having twoconducting segments separated at adjacent edges by an insulating gap, aplurality of annular ring members rotatably mounted on said commutatorcylinder, a brush carried by each of said rings and arranged to engagethe commutator cylinder, each of said brushes having a contact endadapted to lie out of contact with either segment of the commutatorcylinder when adjusted to a position in contact with said cylindermidway of the gap, and means for individually moving each of said ringmembers to adjust said brushes.

6. A selector control mechanism for an electrlcal remote control systemfor radio receiving apparatus and the like, including a control shaft,

a commutator cylinder mounted on said shaft, said cylinder having twoconducting segments separated at adjacent edges by an insulating gap,

a plurality of annular ring members rotatably mounted on said commutatorcylinder, a brush carried by each of said rings and arranged to engagethe commutator cylinder, each of said 3 brushes having a contactendadapted to lie out of contact with either segment of the commutatorcylinder when adjusted to a position in contact with the commutatorcylinder midway of the gap, and means for individually moving each ofsaid ring members to adjust said brushes, said means being adapted tohold said ring members in adjusted positions, and including gear teethon the peripheries of said members, worms engaging said teeth, shafts onwhich said worms are mounted and control knobs for rotating said shafts.

CHAS. P. GEYH.

